Deadlift
The deadlift is the final lift performed of the three in a powerlifting competition. Perhaps the world's oldest lift, it consists of lifting a weight positioned in front of the lifter on the floor, and standing fully upright. A closer examination of the biomechanics and physiology associated with performing a deadlift however reveals that it is anything but simple, and as with each of the other two lifts of powerlifting, involves nearly every muscle in the body in a complex kinetic chain to produce maximal force. In the deadlift, the starting position of the weight on the ground, anterior to the lifter's center of mass, changes the kinetics, and accordingly the kinematics, of the lift in relation to the squat with which it is commonly compared. While the squat emphasizes both hip, knee, and ankle movement to maintain the weight above the lifter's foot, the increased distance of the weight from the lifter's hip forces him or her to rely more heavily upon its musculature to produce torque. Additionally, the lifter's lower limbs themselves prevent him or her from rolling the bar over the top of the normal center of gravity, thus creating the emphasis of the deadlift as a "pull," distinct from the squat. Deadlift Phases The deadlift is commonly broken down into three phases or positions: the initial starting position with the weight on the floor, the transitionary or intermediate position as the bar passes above the knee, and the final position or "lockout" of the hip in full extension with the body upright. Initial Position The lifter leans over the bar in a partial squat, with the lumbar spine straight and scapulae tightly depressed and adducted. With the elbows fully extended, the lifter grips the bar rests against the lifter's shins. To begin, the lifter extends the hips and to a lesser extent, the knees, to bring the bar vertically upward along the shin, minimizing the distance from the axis of rotation, the hip. Intermediate Position As the bar passes the patella, the lifter exerts greater force with the knee extensors, bringing the body forward as the bar now has room to drift more closely to the lifter's center of mass. Lockout At lockout, the lifter maximally contracts the gluteal muscles to pull the hip into full extension as the knees reach full extension. The spine remains locked with only a small lumbar arch, the scapulae remain retracted and depressed, and the elbows remain isometrically locked for the entirety of the lift. After successful performance, the lifter reverses these steps, breaking first at the hips and either slowly lowering, or dropping the weight after it passes anterior to the knee. Safety and the Deadlift Few other lifts cause the public to cringe as much as an athlete bending over to lift a maximal amount of weight using his hips and back. Injuries to the spine do occur, but only when form has broken down or is ignored. Done properly, the deadlift is as safe as any other lift and can actually train the neuromuscular system to resist spinal injuries in the future by cementing proper lifting technique in the lifter. Rounding of the Spine As described above, the primary access of rotation is the lifter's hip joint. This is where a majority of the angular displacement and the applied torque should occcur. It is important for the spinal column to remain in neutral posture throughout the lift, and to be stabilized isometrically by the erector spinae group, to prevent injury from shear forces. Rounding of the spine may shorten the moment arm of the weight while it is being lifted, but compromises the spine's stability and dramatically increases the risk of injury by limiting the lumbar musculature's capable role of resisting shear forces [Reference ]. Biceps Tendon Tear Failure to fully extend the elbow during the initial phase of the lift from the floor or failure to maintain extension throughout the lift can result in a very fast onset of a magnitude of stress that the elbow tendons were never designed or expected to handle. Consider shifting the heavy weights performed during deadlifting into a biceps curl, and the effect becomes unsurprising. Even a brief moment of flexion at the elbow can have disastrous consequences. This is especially common on the supinated arm while the athlete is utilizing a mixed grip. Lifters will frequently supinate one hand while attempting very heavy weights to prevent the bar from rolling and reduce the amount of grip strength necessary for a given weight. This does not inherently predispose a lifter to greater injury if the arm remains in full extension, but lifters have a tendency to flex with the supinated hand while exerting maximal effort on the bar, frequently resulting in a torn biceps tendon. Lifting Styles: Conventional and Sumo The more common of the two styles of performing a deadlift is known as the conventional style. In this style, the lifter sets up with his arms outside his legs, while the other style, known as sumo, has a lifter set up with his arms inside his legs. Each style has specific advantages and disadvantages regarding different aspects of lifting the weight, but both methods are generally accepted throughout powerlifting, and the choice of which variation to use depends on the lifter's individual structural differences, training goal, and simple preference. The conventional style requires that the hands be placed no closer together than the outside of the lifter's knees, generally placed at shoulder width. This limits the potential reduction in total range of motion the lifter must go through, resulting in a more difficult lift. Additionally, the narrow position of the feet requires the legs to extend sagitally further from the primary axis of rotation of the lift, the hips. This again increases the range of motion that the lifter must go through, and more importantly, increases the resistive, gravitational torque applied by the bar by way of an increased lever arm. The sumo deadlift was devised as a way to alleviate both of these drawbacks. By placing the hands as far inward as possible, the lifter can maximize the vertical component of his arms and thereby decrease the range of motion of the lift. With the lifter's hips rotated externally and feet placed further apart, the bar can also be moved closer to the lifter's axis of rotation. Despite these advantages, powerlifters as a whole continue to lift nearly equivalent weights regardless of style. In fact, the current world record for heaviest raw deadlift was done by Benedikt Magnusson using the conventional style. The physical structure and anthropometry play a large role in determining the optimum style for a given person. Generally those with shorter arms in relation to their torso have an advantage when pulling sumo, while those with elongated arms will find conventional preferential [Reference ]. Additionally, EMG shows that hamstrings are more active during conventional style than in sumo [Reference ]. Other Variations Many other variations of the basic concept of lifting a dead weight from the floor exist, and are largely used for targetting weaknesses in specific stages or muscle groups of the normal lift, or when injury prevents the execution of the normal lift safely. Rack Pulls Essentially just a partial deadlift, with the weight starting from a higher position than the lifter's feet. This reduction in range of motion provides many of the benefits of a deadlift to lifters with a safety hazard of operating through the full range of motion. Maintaining a more upright posture reduces the strong shear forces on the spine, at a maximum during the start of the lift due to the spine's more horizontal angle. Rack pulls are often used in the training of healthy lifters as well to provide a focus on the maximal "locking out" of the lift, to allow for heavier weights at this stage by skipping the potentially inhibitive starting portion of the lift, or to correct gluteal inactivity by applying stress at its point of highest activation during the lift [Reference ]. Deficit Deadlift With the opposite problem that would necessitate rack pulls, a healthy lifter experiencing problems in the starting portion of the lift may choose to maximize his flexibility and strength during the initial lift, by increasing the range of motion even further. In a deficit deadlift, the lifter stands on an elevated surface some distance above the floor where the bar is resting. Snatch-Grip Deadlift Must like a deficit deadlift, utilizing an extra-wide grip of the bar, as would be done while performing the olympic snatch, the lifter forces an increase in the lift's range of motion. The widened arm position also significantly changes the muscular activity of the shoulder stabilizers and muscles of the upper back Citation, as more force is needed to maintain upper limb stability in the transverse plane with the increased moment arm. Stiff-Legged/Romanian Deadlift Done with much lower total weight to prevent injury, the lifter maintains only a slight flexion in his or her knees throughout the entire lift and rotates only through his or her hips. This shifts a great deal of stress to the hip extensors and particularly the hamstrings in their role as a hip extensor, as they are stretched completely across their two joints. Trap Bars/Hex Bars A trap bar's design allows the lifter to place the weight directly over his center of gravity, transitioning the deadlift's kinematics into those much more like a squat, specifically a hack squat . See the Equipment page for more details. The Deadlift in Other Sports The deadlift has gained great popularity outside of powerlifting cirlces. Athletic training utilizes the deadlift to improve the maximal strength of the posterior chain, used in a number of situations within virtually any sport requiring strength, such as a football lineman pushing upward on his opponent or a wrestler suplexing his opponent. Bodybuilder and eight time Mr. Olympia Ronnie Coleman integrated many aspects of powerlifting into his bodybuilding training regimen, including the use of heavy weight for low reps and namely, deadlifting to build his powerful physique. The deadlift offers prospects to ergonomics as well. In many manual labor jobs a worker will need to lift and carry a heavy object from the floor. Non-labor intensive occupations may still benefit from the strengthening of the posterior postural muscles of the thoracic spine and scapula to counterract protracted scapulae, and thoracic kyphosis that have become increasingly prevalent in jobs requiring the worker to maintain a sitting posture for an extended period of time. Even beyond athletic and job performance, a basic understanding of and strength with the deadlift could serve any given person of the population better throughout daily life. How often do you pick up heavy or cumbersome objects around your home? Do you do so with the minimal risk of injury and discomfort?